Polycarbonate windows are widely used because of their resistance to breakage. However, polycarbonate windows, especially in airplanes and supersonic aircraft, for instance, are subject to abrasion and clouding due to the severe atmospheric conditions encountered at high speeds. This problem is a menace to both civilian and military aircraft.
Attempts to overcome this problem using silicone polymers and acrylic resin coatings for instance, met with limited success largely because such coatings lacked adequate adhesion and suffered loss of clarity.